Educational information, not medical advice — ask your doctor or midwife.
Bixa orellana is a small tropical tree, better known as annatto or achiote. Its seeds carry a bright red-orange coat. That coat is the source of annatto, one of the world's oldest food dyes.
Most people meet it as a colouring, not a remedy. It tints cheese, butter, rice, sausage and snack foods. The seeds, leaves and bark are also sold as teas, powders, pastes and capsules.
Healers across the Amazon and Central America used the plant for skin, fever and stomach complaints. Long use is not proof that it works, and it is not proof that it is safe.
Here is the honest verdict. As a food colour, annatto is widely used and well regulated. As a health supplement, good human evidence is close to absent.
No one has shown how it works in people, because no health effect is proven in people.
The seed coat is packed with orange pigments. In test tubes, these pigments soak up reactive molecules that can damage cells. Whether that happens in your body at food or supplement doses is unknown.
In animal studies, seed extracts have lowered blood sugar. The doses were high and the results were mixed. This has not been confirmed in good human trials.
In laboratory tests, leaf and seed extracts slow the growth of some bacteria and fungi. That is a dish result. It does not mean a tea or capsule will treat an infection.
Some rodent work also points to a mild water pill (diuretic) effect and lower blood pressure. Again, this is animal data only.
Annatto reaches you in several forms:
- Whole seeds, used to colour cooking oil or stews. - Ground seed powder and achiote paste, sold as a food seasoning. - Oil-based bixin and water-based norbixin colour, used by food makers.
- Capsules or tablets of seed powder or extract. - Dried leaves sold for tea. - Skin creams, soaps and body paints.
Food-grade colour and supplement-strength capsules are not the same thing. The amount you eat in cheese is tiny.
Annatto has been used in the Americas for thousands of years. Peoples of the Amazon and Central America ground the seeds into a red paste.
The paste coloured skin, hair, cloth and pottery. It was worn in ritual and used as a body covering against sun and insects. Spanish writers recorded the Aztec habit of adding it to chocolate drinks.
Folk healers also used leaf teas and seed preparations for fever, stomach upset, burns and snakebite. These were traditional practices recorded by observers, not tested treatments.
Get emergency help at once if you have swelling of the lips, tongue or throat, trouble breathing, or hives spreading over your body. These are signs of a severe allergic reaction.
Stop and see a doctor if you get shaking, sweating, dizziness or confusion, which can mean low blood sugar.
See your doctor if a fever, wound or skin problem is not settling, or if stomach symptoms last more than a few days.
Annatto is an approved food colour in the UK and EU, listed as E160b. The US FDA also allows it as a colour additive. Sold as a capsule or tea, it is a food supplement, not a licensed medicine, so no health claim is approved.
Evidence grades and traditional-use labels are explained in our methodology. Nothing here is medical advice.
What it is typically used for, usual dose, cautions, and the study behind it where real trial data exists.
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